Vulnerability Intelligence Report
Microsoft Exchange Server Remote Code Execution Vulnerability
CVE-2021-42321
Microsoft Exchange Server Remote Code Execution Vulnerability
CISA KEV
SSVC: Active Exploitation
CVSS Base Score
8.8
HIGH
Exploitability:2.9
Impact Score:5.9
EPSS Probability:90.39%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 21 | 15.01.0 < 15.01.2308.020 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 22 | 15.0.0 < 15.01.2375.017 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 10 | 15.02.0 < 15.02.0792.019 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 11 | 15.02.0 < 15.02.0986.014 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Microsoft Corporation · Vendor · USA |
| Reserved | 2021-10-12T00:00:00 |
| Published | 2021-11-10T00:47:43 |
| Patch Date | 2021-11-09 |
| Last Updated | 2026-08-19T16:27:07 |
Community Chatter & Buzz